Read the passage and answer the following question.
During the Ming Dynasty, what is now the city of Shanghai was a part of Jiangsu Province (with a small partin zhejiang Province). While Shanghai had become a county seat in the Yuan Dynasty, it remained relatively a small town.
Its location at the mouth of the Yangtze led to its development as coastal trade developed during the reign of the Qianlong emperor in the Qing Dynasty. Gradually, the port of Shanghai surpassed the port of Ningbo and the port of Guangzhou to became the largest port of China at the time.
In 1842, Shanghai became a treaty port, thus developing into an international commercial city. By the early 20th century, it was the largest city in the Far East, and the largest port in the Far East.
In 1949, with the Communist takeover in Shanghai, overseas trade was cut dramatically. The economic policy of the People’s Republic had a crippling effect on Shanghai’s infrastructure and capital development.
In 1991, the central government allowed Shanghai to initiate economic reform. Since then, the port of Shanghai has developed at an increasing pace. By 2005, the Yangshan deep water port was built on the Yangshan islands, a group of islands in Hangzhou Bay, linked to Shanghai by the Donghai Bridge. This development allowed the port to overcome shallow water conditions in its current location, and to rival another deep-water port, the nearby Ningbo-Zhoushan port.
Question – Which of the following are described in this passage?